1. Field of the Invention
The present invention generally relates to an electrical connector system, and, more particularly, to a two-piece component of a connector having a terminal position assurance feature for giving mechanical and visual assurance that the terminals are properly installed in the connector component and for locking the terminals in position.
2. Description of the Prior Art
An electrical connector typically includes a pair of mateable connector housing components or halves constructed from a dielectric material. The housing halves are usually identified as a plug half (or male half) and a socket half (also referred to as the receptacle half or female half). The two connector halves have complementary inter-engaging conductive terminals for completing an electrical circuit when the housing halves are fully and properly mated. The plug half generally has one or more projecting conductive pins which are inserted into one or more conductive receptacles or sockets on the socket half. The contact between the pin terminals and socket terminals forms the electrical connection between the two connector halves.
The pin and socket terminals are typically small components manufactured from wire and stamped sheet metal materials. Proper placement of the terminals in the dielectric housings of the connector halves is important for ensuring an electrical connection. If one or more terminals is not seated properly in its respective housing half, then a poor quality or incomplete electrical connection may exist when the two housing halves are assembled. This improper seating of the terminals may occur, for example, during initial placement of the terminals into the connector housing, during processing or shipment prior to final assembly of the connector halves, during assembly of the connector halves, or following assembly due to vibrations, external stress, or the like, such as if a terminal is pulled from its fully seated position within the connector housing.
Failures due to improper terminal seating are of particular concern in the automotive industry. Connectors on vehicles are subjected to extreme weather conditions, continual vibrations, and occasional rough treatment during repair, maintenance, or the like. To avoid connector failures, the automotive industry may require that connectors include some form of terminal position assurance ("TPA") system to provide a visual, mechanical, or other type of assurance that the terminals are properly installed in the connector. A locking mechanism for holding the terminals in the connector housing may also be required. The TPA arrangement may be part of this locking action, or may be separate from the locking mechanism.
In the past, different techniques have been used to provide terminal position assurance for terminals within a connector housing, including pin and socket type terminal systems. For example, U.S. Pat. No. 5,522,740, to Plocek et al., discloses an electrical connector having a TPA insert which detects whether or not a terminal is properly installed. The connector includes the TPA insert which contains a number of terminal-receiving passages. The TPA insert is partially inserted into a connector housing, and the terminals are then inserted into the passages. The terminals include first openings which receive a locking finger portion of the connector housing when the terminals are inserted. Following insertion of all the terminals, the TPA insert is moved to the fully-inserted position, and locking arms on the TPA insert enter second openings in the terminals. If a terminal is not quite properly seated, the TPA insert can seat the terminal when the TPA insert is moved forward. When the TPA insert is in the forward position, the terminals are locked in place. Because the terminals are engaged with both the housing and the TPA insert, a special tool is required to remove the TPA insert or terminals from the final locked position.
U.S. Pat. No. 5,573,430, to Hatagishi, shows another type of two-piece connector component which includes a housing portion which receives an insert portion in which a plurality of terminals are mounted. The insert and housing include a number of guide projections, contact projections, and vibration-preventing projections for securely holding the terminals in position following assembly. However, Hatagishi does not appear to include any arrangements for providing a TPA system which will prevent assembly of the insert into the housing if the terminals are not properly seated.
While the prior art connector components and TPA arrangements function effectively for their intended applications, some of the components may be complex to mold, or to assemble and disassemble. Accordingly, it is desirable to provide an alternative connector and TPA arrangement whose functional components enable a simpler and more compact construction than those of the prior art, without sacrificing strength and functionality. The two-piece connector component and TPA system of the present invention provide these and other benefits, and overcome the shortcomings associated with the prior art.